This invention relates generally to the withdrawal or payout of flexible cable under tensile loading from a storage reel, and more particularly to control over such payout.
Payout of cable from a storage reel in mine mooring systems associated with marine vessels, for example, is often plagued by cable damage problems caused by excessive tensile loading. In such installations, the mooring cable is tightly and precisely wound on the storage reel in order to avoid cable deformation and cutting through successive layers of cable turns on the reel under tensile loading when payout is stopped. Payout is controlled by an electrically activated brake connected through a brake shaft to a payout arm that is rotated to peel the cable off a stationary reel.
In such existing mine mooring systems, the cable tensioning forces applied by the payout load, such as a buoyant capsule, were directly transmitted to the cable on the reel creating the aforementioned cable damage problem. Further, such cable payout systems required a high braking power capacity and large diameter cable to meet the cable loading demands associated with a correspondingly high anchor depth capability.
It is therefore an important object of the present invention to regulate payout of an elongated flexible cable, wound upon a storage reel, under control of a brake with reduced braking capacity while avoiding the aforementioned cable tension damaging problem.
An additional object of the invention in accordance with the foregoing object is to enable use of smaller diameter cable made of metallic or synthetic material in payout control systems of the aforementioned types.